Table 2. Cooperative effects of boronic acid–DMAPO on the dehydrative condensation reaction ^a .

Entry	ArB(OH)2	Yield b , c (%) of PhEtCHCONHBn	Yield b , d (%) of PhCONHBn
1	2	99 [<5]	97 [<5]
2	PhB(OH)2	<5 [<5]	<5 [<5]
3	4b	92 [<5]	20 [8]
4	3	7 [15]	80 [95]

^a0.5 mmol of carboxylic acid and 0.5 mmol of benzylamine were used in the presence of 5 mol% of ArB(OH)₂ and 0 or 5 mol% of DMAPO.

^bThe results when both catalysts were used are shown. For comparison, the results without DMAPO are shown in brackets.

^cConditions: fluorobenzene (bp. 85 °C), 17 h.

^dConditions: toluene (bp. 110 °C), 4 h.